Large increase in plate stresses due to Temperature loading

Hi All,

I have been analyzing a slab using plate elements and using the plate summary to design it. But the owner asked to consider temperature loads in the design. I have read posts regarding the temperature loads here in this forum and followed it. But when I finished running the file, this caused sudden increase in the stresses even if there is only small difference in temperature.

Could someone please check my STAAD file for verification? 

* Slab is inside a concrete silo. Thickness = 2000mm

* Top temperature is 40 deg. C and bottom temperature is 30 deg. C. 

*Ambient temperature is also 30 deg. C

* This slab is supported by a corbel around the silo.

I appreciate your replies on this.

Thank you.

RC-SILO_MSL+16.3_SLAB_40-30.stdPDF